Pintle wires



April 13, 1965 E. RACE PINTLE wIREs Filed May s, 196s I4 Z16 22 L20 16 United States Patent O 3,177,539 PINTLE WIRES Edward Race, Blackburn, England, assgnor to Scapa Dryers Limited, Blackburn, England Filed May 8, 1963, Ser. No. 278,921 9 Claims. (Cl. 24-33) This invention relates to the pintle or of lacing wires used in mechanical seams (commonly known as clipper seams) which are used in belts and other industrial fabrics side into each end of the fabric, or into lengths of webbing stitched to the respective ends of the fabric, and through which, after the hooks or clips on one end of the fabric have been intermeshed with those on the other end, a pintle or lacing wire is inserted to complete the seam.

These pintle wires are subject to a very considerable radial pressure due to the tension in the fabric and `they are also subject to a great deal of peripheral friction due to the hinging movement of the clips around them These f two factors result in the wearing of circumferential grooves in the pintle wire, in most cases so deep as to make it impossible to withdraw the wire endwise from the seam, and even insome cases so deep as to cause rupture of the pintle wire. 'Again, for a perfect seam, said clips should be able to move freely in the axial direction of the pintle wire if and when a belt contracts in width, as may often be the case. The pintle wires cannot be of any great diameter since ytheir diameter is governed by the size of the clips through which they pass, which in turn is governed by ythe permissive thickness of the seam and this thickness should not greatly exceed the thickness of the felt. As a result of all this the pintle wires are of necessity subjected to a high Wear rate and, in too many instances, the :service life of a very costly dryer felt is determined by the relatively short life of the pintle wire in its seam, since the rupturing of a seam may result not only in irrepairable damage to the felt, but also to adjacent felts in the machine n and even to the machine itself.

Originally, the pintle wires of clipper seams were made of stranded mild steel or Phosphor bronze, and later they were made of stainless steel, but it was found in practice that thosel metal Wires either wore too quickly or were n too stiifand caused a rippling in the felt, which rippling was not only a source of damage to the paper being manufactured, but also resulted in rapid wearing of those of the wire clips standing proud at the crests of the ripples.

Later, yis was proposed to use a stranded metal core protected byynylon coating, the metal in this case being stainless steel vor mild steel or Phosphor bronze, but it was found that although the nylon coating had greater wear resistance than the bare stranded metal formerly used, its frictional resistance to the movement of the metal clips over it was so great as to prevent the seam contracting widthW-ise of the felt when the felt itself contracted. This also set up undesirable rippling fin the felt. It has recently been proposed to make a pintle Wire by braiding synthetic yarns of high abrasion resistance on to a stranded metal core and to coat the assembly, with a synthetic resin coating. This wire has been an improvement so far as preventing rippling is concerned but it has the disadvantage that it kinks easily, and even the smallest kink results in a more rapid Wearing away at that point.

The wire to be used in clipper seams is supplied to the users in coils. In the uncoiling of the wire for threading rapid, which again leads to rupture of the seam.

3,177,539 Patented Apr. 13, 1965 ICC a length of it through the intermeshed clips of a seam it frequently happens that a loop or turn of the coil is pulled across the coil and is thereby contracted and, if this contraction goes to the minimum size of loop it sets up a permanent kink in the wire. Similar kinking may occur if the wire happens to be lying on the ground with crossing loops and is stepped on or run over by a truck. Another source of kinking or lumpiness in the wire, in the case of a wire with a stranded metal core, results from unbalance and consequent snarling in the strands of the core. As it is almost impossible to Istraighten out a kink, at least without removing or damaging the outer braiding or/ and resin coating, many wires become useless unnecessarily. Of greater concern is the fact that these kinks are not readily discernible, and the installation of a kinked pintle wire can be disastrous in terms of damaged felts and lost paper production.

Another disadvantage with the said resin-coated braided pintle wires with metal cores is that, when some of the clips on the belt have worn through the coated braid, the rate of wear on the metal core at those points is extremely It is apparent, therefore, that disadvantages arise whenever a metal component is incorporated in the pintle wire of a clipper seam.

It is the object of the present invent-ion to provide a form of pintle wire for a clipper seam which has no metal component and is free from the disadvantages of all types hitherto known, in particular that it will not kink if the loops or turns of a coil are pulled transversely of the axis of the coil, that it has a high degree of wear-resistance and has a low co-eiiicient of friction against metal wire clips, both axially and circumferentially, and that it is not subject to unevenness due to snarling. The improved pintle Wires therefore have a much longer useful life than any previously known, and result in a more etcient use of the felts.

A pintle wire according to this invention comprises a central core of a synthetic plastic material which has a high resistance to abrasion, and which has a torsional resilience sufficient to allow it to yield under torsional stress and comprises also a braiding of wear-resistant synthetic material around said core, the braiding having been resin coated after its application to the core. The reference to yielding under torsional stress refers to the fact that -if a kink tends to form whilst the wire is pulled in the direction of its length, instead of the stresses at the kink being resisted, as with metal, and eventually causing a permanent set, they cause the material of the core to twist over a distance from each side of the kink and thereby allow the kink to straighten out without permanent set. Synthetic materials suitable for the core of the improved wire are nylon, acrylic resins and polyester resins.

The selected core of the improved pintle wire may be a monoilament or a multi-filament core. When a multifilament core is used, it may be resin-treated prior to being covered with braid as by coating it with resinas shown at 2lb (FIG. 4).

lt is conceivable also that with some of the'synthetic materials named the core could comprise a yarn or yarns spun from staple libres instead of being a monoor multifilament core.

The invention, in its preferred form, provides a pintle wire for a clipper seam comprising a monolilament nylon core jacketed in a tubular braid consisting of continuous filament yarns of nylon or Terylene (Terylene is a registered trademark) so as completely to be concealed therein and wherein, after braiding, the jacket was resin coated. ln some cases there may be two co-axial layers of braiding separately applied, in which case the iirst layer may or may not be resin coated but the second layer will allWays be resin coated- The resinV being applied to the`onter.1ayer.,

' was 0.080"'.`

Y filamentcore of FIG.3.

through the single layer braid andlthronghthe inner layerv of a two-layer braid, on to tllecore, so as to Vbond these components together as a unit, lorfitmaybe'arranged that, ina double braiding technique only lightcoatingv is applied to 'the rst'layer of braid Vso 'Vasto enable this layer to move relatively to the core,'ra

YSuitable .resins for Y formaldehyde, phenol-formaldehyde, melannnefformaldehyde and epoxy'resins.

heavier, Coating Furtherl y alternatives ,Y are [epoxyuse in the ,coatingprocessarefureaY bonded molybdenum di-sulphide land Aunsaturated lp'oly-y ester resin dissolved inV styrene.

. The invention willV now be described `With reference to fr the accompanying drawingrwherein:

, FIG..1 is a plan of al portionof a clipper seamv such as might'be found'in apaper-machine felt;

FIG. 2 is: anend view ofthe seam; FIG. 3 is a view of'one form of Wire with some parts removed so as more clearlyV to illustrate the construction; andV fof nylon, a'crylicrresinandV polyester resin.

v 3.- A pintle wire according to claim 1, 'n which :the syn theticcore is a nionoflamentselectedA from ithe'rgroup y consisting of nylon,I acrylic resinfand polyesterresin. 4. A pintle WireY according to claim 1, inf'which the syntheticfcore v is a. multilament Vselected from `thel group' the improved pintle f FIG. 4 is a fragmentary view, similaritoFIG. 3, 1111115'.` v

trating a modification.

AsY shown iin'FIGs. 1Y and armenager. the non-nien! lar-Woven felt'l are Vbutted together'at 12 "afterhaving attached to them' the webbing strips 14,16, which carry the interrnershg Wire clips 118', 20. y After the vrelative Y intermeshingof these clips, afpintle Wire, indicated geni FIGS. 1 and `2 isjthreaded 'through themy Y constituting the lseam asfa hinge, A'Yrepresentative Aseam $0 of this character is setV forth in Unitedy States patentto lerally asv 22 in Hall, No. 2,629,909, dated March 3, 195,3,

consisting of nylon, acryliclresin and polyester' resin. y 5. A pintle Wire according toclaimv lyinrwhich thesynthetic core'is a multilamentselected from fthe'group lconsisting of nylon;V acrylic resinandA polyester resin andA av coating of Isyntheticfresin,covering said core within saidflayer of braiding'.Y g" v .l

x f6; 'Apintle Wire fora'clipperxfseain, comprising acentral cylindrical coreof a synthetic plastic material which has ahigh resistance toiabrasion, Vsaid orebeing flexible transversely of itsllengthy and having a. hightorsional resilience' .sufficient to alloyvf it tolyield'under, a torsional Vstress Whichfwouldotherwise ucause kinking, and conn' f 'prising also a rstflayer 'of'braivd of Wear-resistant synthetic material covering said core, a resin' coating'on said f "irsft' layerg'a second', layer of braid of' wear-resistant syn- Y .thetic'material ,overlying said resincoating and a second VReferring nowj` toFIGf/B, the pintrlerwire `islshfovvn .Y

more detail as comprising a solidY cylindricalcore'21,132. rst layer of braiding 23'onwhich isa light Aresingcoating 2S, and a second layer of braiding 27 in vyhichgis afheavier f resin coating V29. YThe core -21 could befor exampleV A nylon monofilament, 0.0427'n diameter,Withfthe.firstk braiding 23y of a high-tenacity ATerylene multi-filament yarn of 250 denier. The assernb1y21-23 has thecoating 25 of epoxy-polyamide resinfwhich Ais subsequently heat-V cured. The second braiding layer 27 is alsoof Terylene and is heat-cured after application of the resin coating 29.r The overall diameterY of the completed` pintle Wire adopted for other embodiments of the invention, YWithin the scope ofthe appended claims. l g 7 Y I In FIG. 4 a modification is illustrated wherein the core 21x is a rnultifilament,V consistingof orcomprisinglany Othery materials and dimensions may vbe.

of the materials suggested as useful in making the 'mond The improved pintle wires thusrprovided are'durable j and non-Vkinking and are highly wear-resistantf Theyi are within the desirable range ofv springiness (flexibility coefficient) While th'ebonded-'on braidingand resin=rcoatensure both ahigh d'egreeiof` wear-resistancerand `a lovv abrasion of theY metal lclips as well as a substantially uni- Y V form'` resistance to Wear through tothe centre, What we claim is; f

tubular Woven fabric to, form an'endlesspapermakers Y felt, said vwire comprising a'cylindrical central'cre of y Y (if) 1. A cylindrical, non-kinking pintle VWire for usein a clipper. hingeV which joinsthe ends of a lengthjof'non` Vof braid.

resinV coatingongthe outersurfacelof said second layer v7*.`Aypintle YWire accordingr to claim `6,V inrwhich the resin coating on' the Ysaid firstv braid layerso penetrates 'the'.braid., as torjbond 'thefbraid' and" thel core' togetherl as aunit. ,Y

y8. A pintle wirev according to lclaimY 6, in which the resinY coating. on thefirst'layer of vbraid is such as toleave the braid free tok move relativelyl to the core., V9. .A pintlel Wire accordingtol claim 1, furtherv characterized in that thesyntheticresin.which lconstitutes the y ,coating ofthe braid is 'selectedl from the group consisting of-'epoxy,polyamide'mixturea urea-formaldehyde, phenolformaldehyde, f epoxy "resins,- melaminek formaldehyde, epoxy-bonded vmolybdenum di-sulphide and unsaturated polyester resindissolved inestyrene." 5 A'Refcarences Cited theExaminer Y *y UNITED STATES PATENTS f ,I 727,077,891, i

L ,fDoNLEY J.l sroCKKING,` `Primary215mm);er. t 

1. A CYLINDRICAL, NON-KINKING PINTLE WIRE FOR USE IN A CLIPPER HINGE WHICH JOINS THE ENDS OF A LENGTH OF NONTUBULAR WOVEN FABRIC TO FORM AN ENDLESS PAPERMAKER''S FLET, SAID WIRE COMPRISING A CYLINDRICAL CENTRAL CORE OF A SYNTHETIC PLASTIC MATERIAL WHICH HAS A HIGH RESISTANCE TO ABRASION, SAID CORE BEING FLEXIBLE TRANSVERSELY OF ITS LENGTH AND HAVING A TORSIONAL RESILIENCE SUFFICIENT TO ALLOW IT TO YIELD UNDER A TORSIONAL STRESS WHICH WOULD OTHERWISE CAUSE KINKING, AND COMPRISING ALSO AT LEAST ONE LAYER OF BRAIDING OF WEAR-RESISTANT SYNTHETIC MATERIAL WHICH EMBRACES AND CONCEALS THE SAID CORE, AND A SYNTHETIC RESIN WHICH COATS AND IMPREGNATES THE BRAIDING. 